package com.hw.basic.myExam;

import java.util.Scanner;

//小红的正整数计数
//小红拿到了一个区间 [l,r]，她想知道该区间内有多少个数是2的倍数。你能帮帮她吗？
public class HJ126 {
    public static void main(String[] args) {
        Scanner sc = new Scanner(System.in);
        while (sc.hasNext()){
            int l = sc.nextInt();
            int r = sc.nextInt();
            int count =0;
            for (int i = l; i <= r; i++) {
                if(i%2==0){
                    count++;
                }
            }
            System.out.println(count);
        }
    }
}
